This invention relates to vehicle seat support structures and particularly to the suspension and weight adjustment mechanisms employed in such structures. Seat support structures commonly employ an upper housing member upon which a seat is mounted, a lower housing member which is mounted upon the vehicle and linkage members interconnecting the housing members. The suspension generally is disposed between the housing members, and the weight adjustment mechanism is coupled to the suspension and supported by the housing.
Commonly a conical coil spring, extending between the housing members, is employed for suspension. The weight adjustment structure, which adapts the seat to the weight of the vehicle operator such that the seat is disposed at the mid-point or half-stroke position of the suspension vertical travel when the operator has positioned himself therein, normally employs a plate abutting the top of the coil spring. A post extends downwardly fro the upper housing member, and the plate and a large gear are disposed thereon. A rotatable shaft having a drive gear at one end and a control knob at the opposite end, is supported by the upper housing member. The drive gear engages the large gear and causes it to move aong the length of the post, thereby enabling the pressure of the plate upon the spring to be varied.
From the foregoing it can be seen that, presently, suspension and weight adjustment structures are generally separate and distinct. Also, weight adjustment structures tend to be somewhat complex.